How do you solve Neighboring Bitwise XOR on LeetCode?

Neighboring Bitwise XOR (LeetCode #2683) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: The XOR of all derived elements must equal 0 for a valid original array.

What is the time complexity of Neighboring Bitwise XOR?

The optimal solution for Neighboring Bitwise XOR runs in O(n) time and uses O(1) space. The complexity is O(n) because we only need to traverse the derived array once to compute the XOR.

What is the brute force solution for Neighboring Bitwise XOR?

The brute force approach for Neighboring Bitwise XOR is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute force approach tries to generate all possible binary arrays and checks if any of them can produce the given derived array. This is straightforward but inefficient. The optimal Optimal Solution approach improves this to O(n).

What algorithm or data structure is used to solve Neighboring Bitwise XOR?

Neighboring Bitwise XOR uses the following concepts: Array, Bit Manipulation. The recommended patterns to study are: Bit Manipulation, Array.

What are the interview tips for Neighboring Bitwise XOR?

Always think about properties of operations like XOR to simplify problems. Check for edge cases first before diving into complex solutions. Practice deriving patterns from examples to recognize underlying rules.

What are common mistakes when solving Neighboring Bitwise XOR?

Overlooking the properties of XOR, leading to unnecessary brute force solutions. Not considering edge cases where derived has only two elements.

#2683

Neighboring Bitwise XOR

Medium

ArrayBit ManipulationBit ManipulationArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(1)	O(1)

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Intuition

Time O(n)Space O(1)

Instead of generating all possible arrays, we can leverage the properties of XOR. The XOR of all elements in the derived array must be 0 for a valid original array to exist.

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Algorithm

2 steps

1Step 1: Calculate the XOR of all elements in the derived array.
2Step 2: If the result is 0, return true; otherwise, return false.

solution.py2 lines

1def is_valid_original(derived):
2    return reduce(lambda x, y: x ^ y, derived) == 0

ℹ

Complexity note: The complexity is O(n) because we only need to traverse the derived array once to compute the XOR.

1The XOR of all derived elements must equal 0 for a valid original array.
2Each element in the original array contributes to two derived elements.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.